IETF Logo Mail Archive

Re: [DNSOP] Benjamin Kaduk's Discuss on draft-ietf-dnsop-dns-capture-format-08: (with DISCUSS and COMMENT)

Tony Finch <dot@dotat.at> Mon, 26 November 2018 14:54 UTC

Return-Path: <dot@dotat.at>
X-Original-To: dnsop@ietfa.amsl.com
Delivered-To: dnsop@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 99423130F16; Mon, 26 Nov 2018 06:54:48 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.199
X-Spam-Level:
X-Spam-Status: No, score=-4.199 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ImLmZ1hMKIu4; Mon, 26 Nov 2018 06:54:46 -0800 (PST)
Received: from ppsw-33.csi.cam.ac.uk (ppsw-33.csi.cam.ac.uk [131.111.8.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id B8CA1130E8F; Mon, 26 Nov 2018 06:54:46 -0800 (PST)
X-Cam-AntiVirus: no malware found
X-Cam-ScannerInfo: http://help.uis.cam.ac.uk/email-scanner-virus
Received: from grey.csi.cam.ac.uk ([131.111.57.57]:54978) by ppsw-33.csi.cam.ac.uk (ppsw.cam.ac.uk [131.111.8.139]:25) with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) id 1gRIHW-00033f-hH (Exim 4.91) (return-path <dot@dotat.at>); Mon, 26 Nov 2018 14:54:38 +0000
Date: Mon, 26 Nov 2018 14:54:38 +0000
From: Tony Finch <dot@dotat.at>
To: Richard Gibson <richard.j.gibson@oracle.com>
cc: Sara Dickinson <sara@sinodun.com>, Benjamin Kaduk <kaduk@mit.edu>, Tim Wicinski <tjw.ietf@gmail.com>, dnsop@ietf.org, dnsop-chairs@ietf.org, The IESG <iesg@ietf.org>, draft-ietf-dnsop-dns-capture-format@ietf.org
In-Reply-To: <8dcbfb75-cee9-99a4-3d9d-817c30efe33b@oracle.com>
Message-ID: <alpine.DEB.2.20.1811261403030.3596@grey.csi.cam.ac.uk>
References: <154258729961.2478.12875770828573692533.idtracker@ietfa.amsl.com> <8538EA17-143F-4855-A658-B78701D9B37C@sinodun.com> <8dcbfb75-cee9-99a4-3d9d-817c30efe33b@oracle.com>
User-Agent: Alpine 2.20 (DEB 67 2015-01-07)
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/Fo20jULPrmsNZKOvsGue0kNlFyw>
Subject: Re: [DNSOP] Benjamin Kaduk's Discuss on draft-ietf-dnsop-dns-capture-format-08: (with DISCUSS and COMMENT)
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: IETF DNSOP WG mailing list <dnsop.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dnsop>, <mailto:dnsop-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dnsop/>
List-Post: <mailto:dnsop@ietf.org>
List-Help: <mailto:dnsop-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dnsop>, <mailto:dnsop-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 26 Nov 2018 14:54:49 -0000

Richard Gibson <richard.j.gibson@oracle.com> wrote:
>
> I am currently going through a similar exercise in another context, and the
> best current text there explicitly characterizes the non-obvious day-based
> accounting of POSIX time.

In general I think it's best to just refer to POSIX on this matter, and
not try to restate the definition. POSIX is very clear and explicit about
the day-based accounting of seconds.

http://pubs.opengroup.org/onlinepubs/9699919799.2016edition/basedefs/V1_chap04.html#tag_04_16

> However, there may be C-DNS purposes that cannot tolerate such
> discontinuities, and they would presumably want to use a continuous monotonic
> timescale with a fixed offset from TAI (as is the case for e.g. GPS time).

That's practically unobtanium on most systems :-) Even if you have PTP
there isn't a fixed PTP epoch, though the SMPTE profile defines it to be
equivalent to POSIX time plus the TAI-UTC value from the IERS / NIST
leapsecond tables.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
disperse power, foster diversity, and nurture creativity

v2.23.0 | Report a Bug | By Email